The present invention relates generally to active signalling systems which are able (i) to penetrate media/instrumentation with high efficiency (optimally), and (ii) to sense, detect or image targets with high accuracy; and more particularly to time-frequency signalling systems which transmit wave packets which take the form of (i) mathematical descriptions of the time-reversed transfer characteristics of the medium and target, and (ii) physical solutions to the equations of motion of those signals with the medium.
It is desirable to resolve a target with high accuracy, and increase the range and the signal-to-noise ratio and the target-signal-to-non-target-signal ratio of the returned signal, of signalling systems such as laser or light detection and ranging (ladar or lidar), radio detection and ranging (radar), IR sensor systems and sound detection and ranging (sonar) systems. One of the standard methods for increasing signal detection is low signal-to-noise environments is the used of matched filter systems in the receiver process. Such matched filtering methods have been described often, e.g., in Minkoff (1992). These matched filtering systems of prior art exist in the reception and processing subsystems of the total signalling system. A common problem with the prior art signalling systems is that the signals used in the transmission system to penetrate, sense, detect or image targets/media are not matched to the target/media, and the matched filter is confined to the receiver/processor-side of the total signalling system. Therefore such systems do not achieve maximum range to target for the energy (Joules) input to the devices, nor can such devices resolve targets with accuracy from designated non-targets or "clutter".
Another standard method for resolving targets with high accuracy is the use of ultrashort pulse waveforms, also known as impulse signals, or time-domain signals, and sometimes inaccurately known as ultrawideband signals. Such signalling systems are also not matched to the target/media and when used with a matched filter in the receiver-processor subsystem also do not achieve maximum range for the energy (Joules) input to the devices, not can such devices resolve targets from clutter with accuracy.